1984-1987 Corvette C4 Front Sway Bar & End Link 22mm Bushings Red Urethane

C4 Corvette Sway Bar Bushing Replacement Guide

Mid America Motorworks Technical Reference
Item 640-949 — 1984-1987 C4 Front Sway Bar and End Link 22MM Bushings Red Urethane

Difficulty: 2 of 5 — Beginner. Basic hand tools required.

About This Guide

This guide applies specifically to 22MM front sway bar bushing applications on 1984-1987 C4 Corvettes. Mid America Motorworks item 640-949 is engineered for C4 Corvettes equipped with a 22MM front sway bar. Before beginning confirm your bar measures 22MM using calipers. If your measurement differs from 22MM refer to the factory reference chart below to identify your correct bushing size and the appropriate Mid America Motorworks bushing kit for your application.

Overview

This guide covers the replacement of front and rear sway bar bushings on 1984-1996 C4 Corvettes. Polyurethane bushings improve cornering response and handling precision by engaging the sway bar faster than original rubber bushings. This is one of the most cost effective handling upgrades available for the C4.

Critical First Step — Measure Before You Order

The C4 was produced from 1984 through 1996. The youngest is now over 30 years old. Factory sway bar configurations may have been changed by previous owners, repair shops or suspension upgrades over that time.

Do not assume your car has its factory original bars.

Before ordering any parts:

• Safely raise and support the vehicle
• Locate the front and rear sway bars
• Measure bar diameter precisely using calipers
• Identify whether each bar is solid or tubular
• Record both measurements
• Cross reference against the factory chart below

You now have two options:

Option A — Restore to factory specification: Use the chart to confirm original diameter for your year and engine. Order that size.

Option B — Match what you have: If bars have been changed, order bushings to match your measured diameter regardless of factory spec.

C4 Corvette Factory Sway Bar Reference Chart

Factory original equipment by year and engine combination

S = Solid Bar. T = Tubular Bar.
This chart reflects factory original equipment. Always measure your actual bar before ordering.

Tools Required

• Floor jack and jack stands or 4x4 wood blocks
• Basic socket set
• Calipers for measuring bar diameter
• Penetrating oil
• Torque wrench
• Drill with bits for bushing removal
• Paint pen or marker for bracket orientation

Parts Required

• Front polyurethane sway bar bushings — sized to your measured bar diameter
• Rear polyurethane sway bar bushings — sized to your measured bar diameter
• Bushing grease — included in kit; use entire package
• Penetrating oil

Select your bushing size from MAM's ascending size range:
24MM — 25MM — 26MM — 30MM
Available: Front / Rear / Complete Car Set

Safety Requirements

• Never work under a vehicle supported only by a floor jack
• Jack both sides of the vehicle equally
• Never attempt bushing removal with the bar in a twisted position — bracket bolts will not release
• Perform bushing burning outdoors only — fumes are hazardous

Preparation — Night Before

Apply penetrating oil to all mounting hardware — front and rear. Allow to soak overnight. This step is not optional on a vehicle 30 or more years old. Rear mounting nuts are particularly prone to corrosion. Adequate soak time prevents stripped or broken fasteners.

Disconnect horn relay wires before beginning front work. This eliminates horn activation during the job.

Front Sway Bar Bushing Replacement

Step 1 — Vehicle preparation

Raise both sides of the vehicle equally using floor jack and jack stands or 4x4 wood blocks under the A-frame. Confirm vehicle is stable and level before proceeding. A twisted sway bar will prevent bracket bolt removal.

Step 2 — Verify bushing size

Confirm ordered bushing diameter matches measured bar diameter before disassembly. Correct any discrepancy before proceeding.

Step 3 — Mark bracket orientation

Using paint pen or marker, mark each mounting bracket position and orientation before removal. Brackets must be reinstalled in original orientation.

Step 4 — Remove front mounting bracket bolts

Eight bolts total secure the front sway bar mounting brackets to the lower A-frame. Remove all eight. Set brackets aside.

Step 5 — Remove old rubber bushings

Two methods available:

Method A — Burn out: Apply torch to old bushing until rubber separates from metal shell. Perform outdoors only. Fumes are toxic. Effective and fast.

Method B — Drill out: Clamp bar end securely in vise. Drill out rubber material. Messier than Method A but safe for indoor use. Requires only a standard drill.

Either method is acceptable. Both produce the same result.

Step 6 — Clean bar surface

Remove all residual rubber, corrosion and debris from bar contact surface before installing new bushings. Clean contact surface ensures proper bushing seating and longevity.

Step 7 — Apply grease

Apply the complete grease package included with your bushing kit to both the bushing bore and bar contact surface. This step is mandatory. Insufficient grease is the primary cause of polyurethane bushing squeak. Do not proceed without fully greasing both surfaces.

Step 8 — Install new bushings

Seat polyurethane bushings fully on bar. Confirm correct positioning before reinstalling brackets.

Step 9 — Reinstall mounting brackets

Return brackets to original marked orientation. Install all eight bolts. Torque to factory specification.

Rear Sway Bar Bushing Replacement

Step 1 — Confirm rear bar diameter

Measure rear bar diameter before removal if not already done. Many C4 rear bars are tubular — confirm solid or tubular designation before ordering. Record measurement.

Step 2 — Locate rear mounting hardware

Rear mounting nuts are more accessible than front hardware. Apply penetrating oil if not done night before. Allow adequate soak time before attempting removal.

Step 3 — Note gas tank emergency straps

Before removing rear mounting bracket, locate and note the position of gas tank emergency straps. These straps prevent fuel tank separation in the event of mount failure. Document their attachment points. They must be reinstalled correctly.

Step 4 — Mark rear bar orientation

CRITICAL STEP — DO NOT SKIP

Mark the top of the rear sway bar clearly with a paint pen before removal. The rear sway bar can be installed inverted. It will bolt into position correctly when inverted. The vehicle will appear normal.

An inverted rear sway bar produces progressive oversteer that develops gradually and worsens over time. The cause is extremely difficult to diagnose. Months may pass before the error is identified.

Mark the bar. Install it correctly.

Step 5 — Remove rear mounting bracket

Remove mounting hardware noting strap positions. Set bracket aside.

Step 6 — Remove old rear bushings

Use drill method as outlined in front procedure. Same process applies.

Step 7 — Clean bar surface

Remove all residual rubber and debris from rear bar contact surface.

Step 8 — Apply grease

Apply complete grease package to bushing bore and bar contact surface. Same discipline as front — use all of it.

Step 9 — Reinstall rear bar

Confirm orientation mark is visible and correctly positioned. Install bar right side up. Reinstall mounting bracket. Reinstall gas tank emergency straps in original position. Torque all hardware to factory specification.

Post Installation Checklist

• All front bracket bolts torqued to spec
• All rear mounting hardware torqued to spec
• Gas tank emergency straps reinstalled correctly
• Horn relay wires reconnected
• Vehicle lowered and level on all four wheels
• Test drive — confirm handling response and absence of abnormal noise
• Re-inspect all hardware after first 100 miles

Troubleshooting

Bushing squeak after installation:

Insufficient grease applied during installation. Remove bushing, clean surfaces, reapply complete grease package and reinstall.

Oversteer or unusual handling after installation:

Inspect rear sway bar orientation immediately. Confirm bar is installed right side up. Remove and reinstall correctly if inverted.

Bracket bolts will not release:

Confirm vehicle is level and bar is not in a twisted position. Apply additional penetrating oil. Allow extended soak time before reattempting.